Opportunities and Limitations of GIS-Based Modeling of Solute Transport at the Regional Scale

2015 ◽  
pp. 19-38 ◽  
Author(s):  
Peter A. Burrough
Keyword(s):  
Solute Transport ◽  
Regional Scale

scholarly journals Editorial of Special Issue “Advances in Groundwater Flow and Solute Transport: Pushing the Hidden Boundary”

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457
Author(s):  
Hongbin Zhan ◽  
Quanrong Wang ◽  
Zhang Wen
Keyword(s):  
Numerical Methods ◽  
Groundwater Flow ◽  
Solute Transport ◽  
Vadose Zone ◽  
Regional Scale ◽  
Chemical Transport ◽  
Low Permeability ◽  
Special Issue ◽  
Flow And Transport ◽  
Wide Range

The theme of this special issue is to explore the new territories beyond conventional subsurface flow and transport theories. We have selected 12 articles in this special issue and these articles cover a wide range of problems including (1) Non-Fickian chemical transport in various environments; (2) Non-Darcian flow; (3) Flow and transport in low-permeability media; (4) Vadose zone process; (5) Regional scale groundwater flow and groundwater-surface interaction; (6) Innovative numerical methods. The major contributions of these papers are summarized in this editorial.

scholarly journals Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

2012 ◽  
Vol 9 (2) ◽  
pp. 2245-2282 ◽  
Author(s):  
J. Moeys ◽  
M. Larsbo ◽  
L. Bergström ◽  
C. D. Brown ◽  
Y. Coquet ◽  
...  
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
General Pattern ◽  
Regional Scale ◽  
Model Parameters ◽  
Model Efficiency ◽  
Fate Model ◽  
Solute Leaching ◽  
Pesticide Leaching

Abstract. Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisation usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

The Hydrogeologic Environment for a Proposed Deep Geologic Repository in Canada for Low and Intermediate Level Radioactive Waste

2011 ◽  
Author(s):  
Jonathan F. Sykes ◽  
Stefano D. Normani ◽  
Yong Yin ◽  
Mark R. Jensen
Keyword(s):  
Radioactive Waste ◽  
Solute Transport ◽  
Regional Scale ◽  
Intermediate Level ◽  
Geologic Repository ◽  
Site Specific ◽  
Ordovician Limestone ◽  
Intermediate Level Radioactive Waste ◽  
The Impact

A Deep Geologic Repository (DGR) for low and intermediate level radioactive waste has been proposed by Ontario Power Generation for the Bruce nuclear site in Ontario, Canada. As proposed the DGR would be constructed at a depth of about 680 m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. This paper describes the hydrogeology of the DGR site developed through both site characterization studies and regional-scale numerical modelling analysis. The analysis provides a framework for the assembly and integration of the site-specific geoscientific data and examines the factors that influence the predicted long-term performance of the geosphere barrier. Flow system evolution was accomplished using both the density-dependent FRAC3DVS-OPG flow and transport model and the two-phase gas and water flow computational model TOUGH2-MP. In the geologic framework of the Province of Ontario, the DGR is located on the eastern flank of the Michigan Basin. Borehole logs covering Southern Ontario combined with site-specific data from 6 deep boreholes have been used to define the structural contours and hydrogeologic properties at the regional-scale of the modelled 31 sedimentary strata that may be partially present above the Precambrian crystalline basement rock. The regional-scale domain encompasses an approximately 18500km2 region extending from Lake Huron to Georgian Bay. The groundwater zone below the Devonian includes units containing stagnant water having high concentrations of total dissolved solids that can exceed 300g/L. The Ordovician sediments are significantly under-pressured. The horizontal hydraulic conductivity for the Cobourg limestone is estimated to be 2 × 10−14 m/s based on straddle-packer hydraulic tests. The low advective velocities in the Cobourg and other Ordovician units result in solute transport that is diffusion dominant with Peclet numbers less than 0.003 for a characteristic length of unity. Long-term simulations that consider future glaciation scenarios include the impact of ice thickness and permafrost. Solute transport in the Ordovician limestone and shale was diffusion dominant in all simulations. The Salina formations of the Upper Silurian prevented the deeper penetration of basal meltwater.

Development of Methodology of Groundwater Flow and Solute Transport Analysis in the Horonobe Area, Hokkaido, Japan

2010 ◽  
Author(s):  
Keisuke Maekawa ◽  
Hitoshi Makino ◽  
Hiroshi Kurikami ◽  
Tadafumi Niizato ◽  
Manabu Inagaki ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Solute Transport ◽  
Safety Assessment ◽  
Regional Scale ◽  
Flow Analysis ◽  
Sea Level Changes ◽  
Site Investigations ◽  
Assessment Techniques ◽  
Transport Analysis ◽  
Specific Safety

It is important for establishment of safety assessment techniques of geological disposal to understand groundwater flow and solute transport accurately. Therefore, we are positioning to confirm an applicability of the techniques in realistic environment as a crucial issue in R&D. We have attempted and planed some relevant studies as below: - A methodology to integrate activities from site investigations to evaluation of solute transport was examined. We have carried out groundwater flow analysis on a regional scale using geological and hydrological information from surface-based investigations at the Horonobe area, and also solute transport analysis based on the information of the trajectory analysis. - We have carried out a preliminary simulation of groundwater flow and salinity concentration distribution using information on climatic and sea-level changes, and evolution of geological structures considering the impacts of natural events and processes. Consequently, we could outline the impacts of natural events and processes on geological environment including hydrogeology, hydrochemistry and their evolutions. - We have been planning to develop and apply a methodology of groundwater flow and solute transport analysis to the shallow part, the Horonobe coastal area and around the URL. These techniques would become a basis for future site specific safety assessment in Japan.

scholarly journals Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

2012 ◽  
Vol 16 (7) ◽  
pp. 2069-2083 ◽  
Author(s):  
J. Moeys ◽  
M. Larsbo ◽  
L. Bergström ◽  
C. D. Brown ◽  
Y. Coquet ◽  
...  
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
General Pattern ◽  
Regional Scale ◽  
Model Parameters ◽  
Model Efficiency ◽  
Fate Model ◽  
Solute Leaching ◽  
Pesticide Leaching

Abstract. Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

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